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I N D U S T R I A L A N D ENGINEERING CHEMISTRY
forms are equivalent for nutritional purposes, this does not guarantee that they will produce equal effects when applied to the soil. The soil hqs certain absorptive effects on ammonia which reduce its mobility. Furthermore, consideration must also be given to the other ions and elements that are introduced in association with the ammonium and nitrate radicals, respectively. A series of experimental tests as carried out in which ammonia salts and nitrates were in part competitors and in part associates. I n these tests nitrate nitrogen was usually somewhat more effective than ammoniacal nitrogen, but a mixture of the two forms gave crop increases that were greater than would be expected from the results secured by separate tests of the two. I n concluding his remarks, Demolon pointed out that French investigations of this problem indicated the general superiority of nitrate nitrogen for sugar beets, maize, and turnips, but not for potatoes and tobacco. For cereals the effects of the two were much the same. Crops growing best on soils that are neutral or slightly alkaline use nitrate nitrogen to better advantage, while those which are adapted to acid soils respond best t o ammonia salts. For crops requiring nitrate nitrogen, the slowing down of the process of nitrification by drought prevents the utilization of ammonia salts. Under such conditions nitrate nitrogen, both because of its form and ability may have a special function to perform.
Irrigation a n d Liming in Relation t o Use of Nitrogenous Fertilizers
J. Galland, agricultural engineer of Paris, presented a paper on irrigation and liming in relation to the use of nitrogenous fertilizers. The mobility of nitrates is such that following periods of heavy rainfall they may be carried below the reach of the roots of plants. If this happens t o be at a time of critical need of nitrogen by the plant, nitrogen starvation may result if only nitrate nitrogen has been applied. Recalling some data of Wilfarth’s, Galland showed that increasing quantities of nitrogen reduced the water requirement of sugar beets from 569, when 0.42 gram of nitrogen was applied, to 383, when nine times as much nitrogen had been used. Irrigation makes it possible t o use ammoniacal salts where without irrigation only nitrates can be employed. Under irrigation, the former may even be superior. Irrigation also changes the time of application of nitrogen fertilizers, delaying that of ammonia salts. Losses by leaching are much reduced if ammonia salts are employed. Under conditions of irrigation, earlier growth of alfalfa can be secured by the use of nitrogen fertilizers, in conjunction with phosphoric acid and potash. I n connection with the use of lime, Galland pointed out that it was not logical to ban the use of ammoniacal fertilizers simply because they tend to make the soil acid. It happens that, while some plants grow best in soils having a pH value greater than 7sugar beets, for example-others prefer a slightly acid soil. BY proper adjustment of acid fertilizers and lime, better results can be secured than if only the alkaline salts are available. Attempts to produce fertilizers containing both lime and ammoniacal salts did not seem a satisfactory answer t o this problem since some plants do not require the addition of the lime.
Fertilizer Problems of I n d i a A suggestive paper was presented by T. H. J. Carroll, assistant director of Agricultural Research of Nitram, Limited, of London. This dealt with fertilizer problems of India and prospects as to fertilizer consumption in that country. Poverty and ignorance both stand in the way of rapid increase in consumption of fertilizers in India. In addition, it is recognized that much investigational work must be done before sufficient information is a t hand as to how to use fertilizers under the great variety of climatic conditions that obtain. It was pointed out that under conditions of drought, small
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applications, repeated a t intervals depending upon the weather, are better than single heavy applications. On the other hand, fertilizers properly used “may sometimes be equivalent to a shower of rain,” since less water is required to produce a pound of dry matter when the crop is well fed. Adequate use of fertilizers may reduce the number of irrigations required. They may serve in part as substitutes for organic manures of which the supply is limited. In general, ammonia salts give better results than nitrates in India. This is true for cotton, sugar cane, rice and tobacco, although in some cases nitrates are preferred for the tobacco. There is reason to believe that concentrated fertilizers, such as ammonium phosphate, have certain economic and crop advantages in India. The evidence in favor of including potash in the fertilizer in India is, according to Carroll, still wanting, although trials are being made with various potash salts in the belief that they may prove helpful in aiding the plant to resist disease and t o prolong its period of vegetative growth. The potentialities of fertilizer consumption in India are enormous. About 250 million acres of land are under cultivation with a possible ultimate consumption of 2 million tons or more of pure nitrogen per year. The problem is one of the ability of the nitrogen industry to supply this element to the farmers a t a price that permits of an economic return, assuming that these farmers can be induced t o follow the practices which experiment station results suggest to be feasible. Concentrated Nitric Acid by A m m o n i a Oxidation u n d e r
Pressure
A technical paper of considerable interest to the producers of nitric acid was read by G. Fauser, engineer of “Montecatini,” SocietO Generale per 1’Industria Mineraria ed Agricola of Milano, Italy. This paper dealt with the production of concentrated nitric acid by the oxidation of ammonia under pressure. It was shown that the rate of oxidation increases very rapidly with an increase in pressure and that absorption is much more readily accomplished with the result that the volume of the absorptions towers can be very materially reduced.
Extension of Tariff on Chemicals in Britain Further extension of the British import duty t o a considerable range of chemicals and allied products is considered likely as the result of the recent decision, which went into effect June 4, making calcium biphosphate of baking powder quality dutiable a t 33.5 per cent, according t o information received a t the Department of Commerce. The finance act places a tax on light hydrocarbon oils, including turpentine, and affects materials entering into the manufacture of various chemical and allied products, such as paints and varnishes, polishes, synthetic camphor, and terpineol, as well as the rubber and other industries. The decision making calcium biphosphate of baking powder quality dutiable a t 33.5 per cent, under the Safeguarding of Industries Act, upon importation into the United Kingdom, was the most conspicuous of the official decisions recently made. Additions to the list of chemicals exempted from duty until the end of the year, however, have been made: among others, lactic acid, metaldehyde, and methyl chloride.
Correction In the article entitled “Abrasion Tests of Rubber Stocks-Containing Various Types of Carbon Black,” by W. B. Plummer and D. J. Beaver, on page 895 of the September, 1928, issue the formula used in Series 2 was omitted from Table I1 on page 897. The formula for this series of compounds was 100 pale crepe, 5 zinc oxide, 4 sulfur, 1 stearic acid, 0.75 D. P. G., 25 black, by weight.
